The effect was at an optimum with 150 lM of thiamine, for both
types of treatments. Similar effects were obtained when barley
plants were sprayed with a solution containing thiamine (Fig. S1).
Similar reductions in aphid numbers were also obtained when seed
soaking treatments were carried out with three other barley genotypes
not near-related to Lina; Golf, CI 16145 and Barke (Fig. S2)
and we conclude that the thiamine effect is not dependent on the
cultivar.